[libvirt] [PATCH 6/7] storage:dir: adapts .refreshVol .refreshPool for ploop volumes

[Ján Tomko]

On Mon, Mar 14, 2016 at 07:00:39PM +0300, Olga Krishtal wrote:
> Refreshes meta-information such as allocation, capacity, format, etc.
> Ploop volumes differ from other volume types. Path to volume is the path
> to directory with image file root.hds and DiskDescriptor.xml.
> https://openvz.org/Ploop/format
> Due to this fact, operations of opening the volume have to be done once
> again. get the information.
> 
> To decide whether the given volume is ploops one, it is necessary to check
> the presence of root.hds and DiskDescriptor.xml files in volumes' directory.
> Only in this case the volume can be manipulated as the ploops one.
> Such strategy helps us to resolve problems that might occure, when we
> upload some other volume type from ploop source.
> 
> Signed-off-by: Olga Krishtal <okrishtal at virtuozzo.com>
> ---
>  src/storage/storage_backend.c    | 62 ++++++++++++++++++++++++++++++++++++--
>  src/storage/storage_backend.h    |  5 ++++
>  src/storage/storage_backend_fs.c | 64 +++++++++++++++++++++++++++++++++++++---
>  src/util/virstoragefile.c        |  7 +++--
>  4 files changed, 129 insertions(+), 9 deletions(-)
> 

> @@ -69,6 +109,7 @@ virStorageBackendProbeTarget(virStorageSourcePtr target,
>      int fd = -1;
>      int ret = -1;
>      int rc;
> +    int format = VIR_STORAGE_FILE_AUTO;
>      virStorageSourcePtr meta = NULL;
>      struct stat sb;
>  
> @@ -84,14 +125,26 @@ virStorageBackendProbeTarget(virStorageSourcePtr target,
>          goto cleanup;
>  
>      if (S_ISDIR(sb.st_mode)) {
> -        target->format = VIR_STORAGE_FILE_DIR;
> -        ret = 0;
> -        goto cleanup;
> +        if (virStorageBackendIsPloopDir(target->path)) {
> +            if (virStorageBackendRedoPloopUpdate(target, &sb, &fd,
> +                                                 VIR_STORAGE_VOL_FS_PROBE_FLAGS)
> +                < 0)
> +                goto cleanup;


> +            /* Refresh information stored in DiskDescriptor.xml according
> +             * to ploop image file content.*/
> +            if (virStorageBackendPloopRestoreDesc(target->path) < 0)
> +                goto cleanup;

Probing a volume should not change its contents - libvirt should only
refresh this XML when it changed the volume.

The rest looks good to me.

Jan